7 wonders, interestingly, uses a good resource mechanic, kind of like magic, but without the tapping.

Tiled Resources:What if we put a resource value in the bottom right-hand corner of some cards, and tiled them like 7 wonders. When that card is discarded from play, it can instead be tiled out for resources. The resource given depends on the critter.

in magic terms, you can play a 1/1 critter for free, and when it dies, it tiles under the character to increase their 'aura'. The 2/2 plains critter requires one tiled resource of the same value. A 5/5 could require up to three or four. Maybe of multiple colors for some, but that would get into more complicated territory.

This could create a sort of natural progression, stepping from one kind of critter to another.

I played a game like this, once. 'Threshhold' I think they called it--it counted the symbols on the cards in play, and in your discard pile. There were land-like things, that had no effect, but had two symbols on them. Nothing played for free, but I think you started with a Faction card in play, that had a symbol on it. The 'count cards in your discard' was both really important and initially confusing. (Elsewise, when someone killed a critter, they also nuked a land).

It did not have multiple colors on it, though. 7 wonders has 7 resources--four brown and 3 gray. Which seems a lot, but which resources you select kind of chooses your strategy for you.

"I can't tell if what you are saying is too profound for me to understand, or just insane".

ShadowFist does something like that--If a card 'costs's GGG, you need to have GGG --somewhere--either in play, or in your discard pile. Supports multiple colors pretty handily, and someone killing your critter mid-calculation doesn't screw with your available resources. Wouldn't work with a Dominion-style 'draw and reshuffle' though.

"I can't tell if what you are saying is too profound for me to understand, or just insane".